1. Field of the Invention
The present invention relates to a flat panel display device, and more particularly, to a plasma display panel which displays images using gas discharge.
2. Description of the Related Art
A plasma display panel is a display device in which a discharge gas is filled between electrodes installed in sealed spaces, and a predetermined voltage is applied to respective electrodes to create a glow discharge, and accordingly ultraviolet rays produced during the glow discharge excite a phosphorous layer to form an image. Since display characteristics of the plasma display panel, such as resolution, brightness, contrast and a field of view are excellent, the plasma display panel is anticipated to be a display device which can replace the existing cathode ray tube.
Such plasma display panels are classified into a direct current type and an alternating current type according to the discharge mechanism, i.e., the driving method. In the direct current type plasma display panel, electrodes are exposed to a discharge gas sealed in respective cells, and the voltage applied across the electrodes is applied across the discharge gas itself. On the other hand, in the alternating current type plasma display panel, since electrodes are isolated from the discharge gas by respective dielectric layers, the electrodes do not absorb charged particles produced during discharge, and instead wall charges are formed to cause a discharge.
Referring to FIGS. 1 and 2, in a conventional plasma display panel, a front substrate 100 made of a transparent material such as glass and a rear substrate 200 are assembled to face each other and form discharge spaces.
On the front substrate 100, stripe-shaped transparent electrodes 110 are equidistantly formed, and stripe-shaped bus electrodes 111 made of highly conductive electrode material, for example, chromium (Cr) or silver (Ag) are formed on one side end of the transparent electrodes 110, respectively to have a narrower width than that of the electrodes 110. Then, the transparent electrodes 110 and the bus electrodes 111 are embedded in a dielectric layer 120.
On the rear substrate 200, stripe-shaped address electrodes 210 are formed to be orthogonal with respect to the transparent electrodes 110 and the bus electrodes 111 of the front substrate 100, and also the address electrodes 210 are embedded in a dielectric layer 220. In addition, a plurality of partition walls 230 are formed on the dielectric layer 220 to define discharge cells 201, and in each discharge cell 201 a phosphorous layer 240 is continuously formed on side surfaces of the partition walls 230 and the bottom surface of the discharge cell 201.
In the conventional plasma display panel configured as above, since light rays emitted from the phosphorous layers 240 of the respective discharge cells 201 can pass through both the front substrate 100 and the rear substrate 200, the light rays emitted from the phosphorous layers 240 can not be effectively utilized, and therefore there is a problem that image brightness of the panel is low. Further, since external light rays L entering through the rear substrate 200 appear in front of the front substrate 100, there is another problem in which image contrast of the panel becomes low.